Adhesive advise needed?

Got a project in the planning stages, and need some advise. It is a sign for the company I work for. I want to attach some laser(or plasma) cut stainless steel sheet metal letters to clear polycarbonate sheet.

I'm thinking something in a 2 sided tape adhesive, that I can apply to the back of the stainless, trim to the edge, then press onto the polycarb. The sign is one-sided, so appearance from the back is not a factor.

It will be out in the weather in the Pacific Northwest. No extreme temperatures, but lots of wet.

Suggestions? 3M or someone must make something that will work in this application.

Thanks, Bill

Reply to
Bill Marrs
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Silicone caulk? Randy

Reply to
Randy Replogle

3M 4016 series.

I've used it for years in electronics assemblies, but the recommended application is signs and displays.

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Reply to
Jim Stewart

I was going to suggest a spray-on adhesive but I like Randy suggestion of silicone caulk better. :-)

Best Regards, Keith Marshall snipped-for-privacy@progressivelogic.com

"I'm not grown up enough to be so old!"

Reply to
Keith Marshall

Silicone caulk, is that the RTV bathtub caulk of old?

If it is, it's been my experience that it sticks well to glass and ceramics, makes absolutely wonderful gas-tight (even helium!) gasketing material, but DOES NOT STICK TO METAL very well.

I'd at least do a test piece before commiting to applying it to expensive work pieces, unless recommended by the manufacturer of the adhesive.

Wolfgang

Randy Replogle wrote:

Reply to
wfhabicher

3M VHB tape.

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Ned Simmons

Reply to
Ned Simmons

Get some Amazing Goop at Home Depot. Works like a champ even in hot temperatures 140-degrees +

Ned Simm> > > Got a project in the planning stages, and need some advise. It is a sign for

Reply to
Weldman

How thick or heavy are the letters? Silicone does work quite well for this but you should rough up the lexan slightly for extra "tooth" #M does make some thapes that are just for this also. Very expensive for the sure fire closed cell foam tapes. You might get them to send you a sample roll that might be enough for the one job. If the letters are heavy then some kind of post with a hole in the lexan will be foolproof. You don't want it to fall off and hit smeone or a car.

Reply to
daniel peterman

Silicon adhesive caulk was invented to attach plexiglass windows to aluminum window frames in airliners.

Silicon adhesive caulk sticks very well to *clean* metal. It's amazing how little grease is enough to prevent adhesion. Try wet-sanding the metal with a little TSP in water as the "wet", rinsing well, and toweling dry. Wear gloves to prevent the people grease from contaminating everything.

One thing to be aware of is that with silicon rubber, one can have too thin a glue line if one is attaching materials of different thermal or humidity expansion coefficients. There has to be enough rubber in between so that the resulting strain is well below what the rubber can tolerate, or the rubber will tear.

Joe Gwinn

Reply to
Joseph Gwinn

Try this stuff. It works great.

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Bert Plank Calgary, Alberta Canada

Reply to
Bert Plank

Call 3M, they are willing to help.

Reply to
Tom Gardner

Joseph,

I'll take your comments under advisement; I have seen glass aquariums (no metal frame) glued up using clear silicone caulk. But I have never seen any metal containers glued up like this. Are you sure that the silicone was not just used as a gasketing material and as a stress isolator to keep the clamping forces off the window panes in the aircraft application?

Just wondering.

Wolfgang

Joseph Gw> >

Reply to
wfhabicher

OK. No idea why, except that perhaps the metal frame isn't needed in that application.

Yes. I picked the story up from some of the early patents listed on the tube.

I also have much personal experience gluing aluminium with silicon adhesive caulk. I recall a test where I glued two pieces of etched aluminum together and let them cure overnight, the overlap being about 3 by 3 cm. It took something like 100 Kg to pull them apart, and from the smell of vinegar, the cure was not complete.

The etching was done with lye in water at room temperature, followed by rinsing and toweling dry. For longer term use, neutralizing the lye with dilute acetic or phosphoric acid might be useful. Anyway, one can get the surface equally clean by wet sanding.

I would just try some experiments.

Joe

Reply to
Joseph Gwinn

I remember hearing (way back when) it was developed as an adhesive for the space shuttle's heat tiles.

Erik

Reply to
Erik

I think it was around before the space shuttle was even on the drawing boards. ( think- think) ...lew...

Reply to
Lew Hartswick

snipped-for-privacy@hotmail.com wrote in article ...

Silicone-based gasketing materials have been used in automobiles for several decades now.

For a number of years, the GM factory part number for Chevrolet rocker cover gaskets - metal-to-metal - was 6BR - the Permatex silicone gasket maker part number.

I have used it generously in race cars for the last several decades....from making gaskets to sealing windows and windshields.

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